The objective of this proposal is to investigate one or more of the following questions by reexamining cohorts formed in 1965-1967, or examining children of those cohorts: 1. What is the ten or twelve year sequelae of a single blood pressure measurement exceeding 140 mm. systolic and/or 90 mm. diastolic when this measurement was obtained during a high school survey? 2. Do the blood pressures of children, now ages 7 thru 11, of mothers in whom preeclampsia was diagnosed differ from those of children of similar age of mothers in whom preeclampsia was not diagnosed? 3. Is the aggregation of blood pressure observed among siblings ages 15 thru 22 diminished (or increased) over time by differeing environmental conditions resulting from the establishment of separate households? 4. Are varying urinary electrolyte excretion levels, pulse rates, weight patterns, growth patterns, socioeconomic levels, or smoking levels associated with either a higher attained blood pressure level or an accelerated increase in blood pressure upon follow-up examinations 6 to 12 years after initial measurements, and further are such associations, if present, influenced by family history of hypertension or of preeclampsia, by the use of oral contraceptive agents, or by intercurrent pregnancy, whether complicated or not complicated by preeclampsia? 5. What is the prognostic importance or implication of a blood pressure measurement obtained during adolescence as related to attained blood pressure 10 to 15 years later and to clinical consequences during the intervening years? This differs from 1 only in that the complete spectrum of blood pressures could be examined.